Question

Decide whether the given x value is a zero of the function.

f(x) = x3 + 5x2 + x + 5; x = –5


Select one:


a. No, because there is more than one zero.

b. No, because substituting the value does/does not make the function equal to zero. Incorrect

c. Yes, because substituting the value does/does not make the function equal to zero.

d. none of the above

Answer 1

@ganeshie8 @thomaster

Answer 2

your funtion is
\(\large f(x) = x^3 + 5x^2 + x + 5\)
right ?

x=-5 is a function zero \(\iff \) f(-5) =0
so check
\(\large f(-5) = (-5)^3 + 5(-5)^2 + (-5) + 5\) if its equal to zero , then x=-5 is a function zero .

Answer 3

so which one is it

Answer 4

-.-
try to check and see , whats the value of f(-5) ?!

Answer 5

I put it in http://www.wolframalpha.com/input/?i=f%28-5 and it says its even

Answer 6

oh its 0

Answer 7

I know the answer isn't b

Answer 8

http://www.wolframalpha.com/input/?i=+%28-5%29^3+%2B+5%28-5%29^2+%2B+%28-5%29+%2B+5

ok good then whats the answer ?

Answer 9

x=-5 is a zero of the function since it satisfies the function when we substitute\[f \left( -5 \right)=0\].
answer will be option c

Answer 10

ok thanks